Overactive Bladder - what is it?
Overactive bladder (or OAB) is a condition that affects 1 in 6 men and women in the UK. People with OAB have difficulty holding on when their bladders are full and often have to rush to the toilet ("urgency"). Patients typically have to pass urine more frequently than normal. Around one third of patients with OAB may find they leak urine before they can reach the toilet (this is called urge incontinence).
Most people pass urine 4 or 5 times a day and can comfortably hold around 300-400ml of urine before they need to go. People with an overactive bladder need to go more often than normal (eg 8 or more times) and may only be able to hold a smaller volume in their bladder. They may also find themselves getting up at night to pass urine (nocturia).
The main symptoms of overactive bladder are:
- urgency (sometimes with incontinence)
- nocturia (getting up at night to pass urine)
What causes an overactive bladder?
The bladder normally holds 300-400ml of urine. When you’re ready to pass urine, the bladder muscle contracts, squeezing urine out through the urethra (the pipe that drains urine out of the body). With an overactive bladder, the bladder muscle can start squeezing before you’re ready, making you need to rush to the toilet or causing urine to pass before you can get there.
In some cases, infection or inflammation within the bladder can make it more sensitive. Other causes include bladder stones, neurological conditions and occasionally bladder tumours. In most cases no underlying cause is found, but assessment by a doctor is advised so that other problems can be ruled out.
Possible underlying causes of OAB:
- bladder infections or cystitis
- inflammation of the bladder
- bladder stones
- bladder tumours
- neurological problems
What is urge incontinence?
Urge incontinence is the urinary leakage preceded by a sudden urgent desire to pass urine. This common complaint affects over 6% of women and many men also. Urge incontinence can occur on its own, but some people have stress incontinence as well (see stress incontinence section.)
The investigation and treatment of urge incontinence is the same as for overactive bladder.